PK04199: DBRF INCORRECTLY ALLOWS USER TO ACCESS BEYOND THE END-OF-FILE AND IN IMS FREE SPACE ELEMENTS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• if you enter an rba on panel fabzps1 that is for a block that is
  beyond the end-of-file, but not beyond end-of-extents, DBRF will
  read and display that block for OSAM db. If you enter an rba tha
  t maps to an IMS free space element in an HD db, DBRF will attem
  pt its segment-searching logic, and if the rba happens to have a
  value that is also a valid IMS segment code, DBRF will interpret
   this rba as a valid IMS segment.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: IMS Database Repair Facility versions 1.1    *
  *                 and 1.2                                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: Fix the error handling for 2 specific   *
  *                      cases. 1) if user enters an OSAM rba    *
  *                      that is beyond EOF, DBR displays an     *
  *                      empty block. 2) if user enters and rba  *
  *                      that is ina free-space element of an HD *
  *                      database, dbr may interpret that data   *
  *                      as a segment                            *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  dbr current code will get 'z028 rba beyond extents' when you
  enter an OSAM rba that is beyond the last extent of the dataset
  this is correct. However, if the rba is beyond the eof,but
  not beyond the last extent,it will display an empty block.
  For HD db,the user may enter an rba that happens to be in a
  free-space element, dbr will try to interpret the data at that
  rba as a segment,and may succeed.
  

Problem conclusion

• before dbr does OSAM read of a block, it runs some code to
  determine if the blockrba is beyond eof, and if so, will
  display 'z028,block rba beyond eof'. Note: for VSAM, eof is
  properly detected...z028 occurs.
  A user may know the rba of a segment in HD db,and access
  that segment via its rba in dbr.  Later, IMS may have
  deleted that segment, in which case a new Free-space element
  is created. Now, if the user brings up dbr and enters that
  rba, DBR will find that it is in the free-space element
  chain, and not attempt to see if a valid segment code
  is at that rba.
  
  
  110Y
  120Y
  FABZMAIN
  FABZPROC
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UK02782 UK02783

Modules/Macros

• FABZMAIN FABZPROC
  

Fix information

• Fixed component name

  IMS DATABASE RE

• Fixed component ID

  5655E0300

Applicable component levels

• R110 PSY UK02782

     UP05/04/27 P F504

• R120 PSY UK02783

     UP05/04/27 P F504

Fix is available

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